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Xcel Energy fires up new High Bridge plant

The lights are actually on at the state's newest power generating facility.

Jim Zyduck, the plant director of the new High Bridge combined cycle plant, said the plant started its first fire last Thursday.

The plant burns natural gas to turn a pair of giant turbines, similar to a jet engine. The exhaust runs through a boiler that powers a pair of steam turbines, squeezing out even more power. It's replacing a coal-fired plant that has stood near downtown St. Paul since 1923.

High Bridge startupMPR Photo/Tim Nelson

Project manager Bill Myers said the new plant has been years in the making.

"We started driving pile in February of 2006. Just this last November, December is when we completed the majority of the construction. The final phase of construction is checking the major pieces of equipment and making sure they're working correctly," said Myers.

Right now, Plant Director Zyduck said the new plant is running at less than 10 percent power. Steam is being released into the winter air, rather than used to generate electricity.

"This process really is a cleansing process of the piping, so we're not throwing any debris or material toward our turbines. It's a normal startup activity. During this process we're generating about 40 megawatts," said Zyduck.

Bill Myers and Jim ZyduckMPR Photo/Tim Nelson

The plant will generate as much as 600 megawatts, more than double the capacity of the old plant next door.

The project is part of a $1 billion upgrade of Xcel Energy power plants in Minnesota. A coal-fired plant in Oak Park Heights got new emissions controls, and the existing Riverside coal-fired plant in Minneapolis is being converted to natural gas.

Xcel officials in St. Paul said they will virtually eliminate some emmissions, like mercury, into the air.

"This new plant, it's a gas-powered fire plant. It's going to be a lot cleaner. In addition, the staffing for a plant this size is considerably smaller -- 30 to 40 people. The old plant we were at 110 people. It's a much more efficient plant," Zyduck explained.

High Bridge plantMPR Photo/Tim Nelson

It'll also better adapt to alternative energy. Coal-fired plants can't quickly adjust to changes in demand or supply. Gas plants can better help even out the ebb and flow of power from sources like wind turbines.

Still, the change isn't without its drawbacks for the old coal plant's customers. A huge paper recycling plant in St. Paul used steam from old boilers at the coal-fired High Bridge plant.

"Xcel should be lauded for its efforts to transition to a less polluting fuel, like natural gas," said Anne Hunt, environmental policy advisor for the city of St. Paul.

"The unintended consequence of this public policy was now Rock-Tenn, Minnesota's largest paper recycler, is forced to burn No. 6 fuel oil. They don't have the state-of-the-art emissions control technology. And they're also burning, when they use No. 6 fuel oil, a more polluting fuel," said Hunt.

The company, the St. Paul Port Authority and Rock-Tenn's neighbors have been trying to figure out a long-term alternative.

Rock-Tenn has suggested burning fuel from processed garbage, referred to as refuse-derived fuel, or RDF.

The idea has set off a firestorm of opposition in St. Paul. City officials are hoping for an alternative such as biomass, or something like the multi-fuel District Energy facility in downtown St. Paul.

In the meantime, Xcel officials expect to have the new High Bridge plant fully operational by May, and they plan to finish work on all their Twin Cities plants by the middle of 2009.

They said they will spend another two years tearing down St. Paul's historic coal-fired plant, including its 560-foot landmark chimney.